Three-dimensional (3D) type sensing systems are commonly used to generate 3D images of a location for use in various applications. For example, such 3D images are used for creating a safe training environment for military operations or civilian activities; for generating topographical maps; or for surveillance of a location. Such sensing systems typically operate by capturing elevation data associated with the location of the target. One example of a 3D type sensing system is a Light Detection and Ranging (LIDAR) system. The LIDAR type 3D sensing systems generate data by recording multiple range echoes from a single pulse of light and generating a frame, sometimes referred to as an image frame. Accordingly, each image frame of LIDAR data includes a collection of points in three dimensions (3D point cloud), which correspond to multiple range echoes within a sensor's aperture. These points can be organized into “voxels” which represent values on a regular grid in a three dimensional space. Voxels used in 3D imaging are analogous to pixels used in the context of 2D imaging devices. These frames can be processed to reconstruct a 3D image of the location of the target. In this regard, each point in the 3D point cloud has an individual x, y and z value, representing the actual surface within the scene in 3D.
A three dimensional (3D) point cloud is a dataset composed of spatial measurement of positions in 3D space (x, y, z), where x and y are cross-range spatial positions and z is height. The 3D data is generated by systems capable of scanning surfaces, such as stereo paired cameras, radars, laser detection and ranging (LADAR) sensors, etc. Point cloud visualization, in general, is of great interest within the defense and geospatial community.
Advances in LADAR systems have been pushing towards 4D data (x, y, z and time, t). These systems are capable of operating in the same way as a video camera operates, at 30 frames per second. Sampling a scene in a 4D domain is very attractive in military and civilian applications. As will be explained, the present invention uses 4D measurements recorded by a LADAR system to generate 3D video.